I finally figured out how to purchase the Wyoming Reciprocal stamp online through the Wyoming Game and Fish site. I used to be confused as to whether that online stamp was for Wyoming residents wanting to fish the Utah side or vice versa. It is for Utah residents wanting to fish the Wyoming side.

When you go into the purchase license section, choose, "other" and it is about in the middle of the list of other licenses available. Still $10 and good for the 2018 year.